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Slide Preparation Method to Preserve Three-dimensional Chromatin Architecture of Testicular Germ Cells
Published on: January 10, 2014
Differential histone modifications mark mouse imprinting control regions during spermatogenesis.
Katia Delaval1, Jérôme Govin, Frédérique Cerqueira
1Institute of Molecular Genetics, CNRS and University of Montpellier II, Montpellier, France.
The EMBO Journal
|January 27, 2007
Summary
Paternally and maternally methylated imprinting control regions (ICRs) exhibit distinct histone modifications during male germ cell development. These epigenetic differences may influence imprint maintenance after fertilization.
Area of Science:
- Epigenetics
- Genomics
- Developmental Biology
Background:
- Imprinting control regions (ICRs) acquire DNA methylation in the male germ line, with some imprints protected from post-fertilization demethylation.
- These protected imprints are maintained throughout development in somatic cells and tissues.
Purpose of the Study:
- To investigate the role of histone modifications in the somatic maintenance of DNA methylation at ICRs.
- To explore how histone modifications during spermatogenesis influence the protection of imprints after fertilization.
Main Methods:
- Assaying chromatin modifications (histone methylation and acetylation) at ICRs in somatic cells and during specific stages of spermatogenesis.
- Comparing histone modification patterns between paternally and maternally methylated ICRs.
Main Results:
- Somatic cells show DNA methylation at ICRs associated with H4-lysine-20 and H3-lysine-9 trimethylation, while the unmethylated allele has H3-lysine-4 dimethylation and H3 acetylation.
- These differential modifications are also present at maternally methylated ICRs, suggesting a role in imprint maintenance.
- During spermatogenesis preceding histone-to-protamine exchange, maternally methylated ICRs are enriched for H3-lysine-4 methylation and H3 acetylation, which are absent at paternally methylated ICRs. H4 acetylation is enriched at all analyzed regions.
Conclusions:
- Paternally and maternally methylated ICRs possess distinct histone modification profiles during early spermatogenesis.
- These epigenetic differences may dictate how ICRs form specific structures later in spermatogenesis, impacting post-fertilization imprint stability.
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